Post-Maintenance First Test Pass Calculator

Use one process, asset or item scope, reporting period, cutoff, measurement unit, and written classification rule across both values. Every intervention uses a comparable first-test and pass rule. Adjustments, retests, partial tests, deferred tests, and repeated faults use explicit treatment. Reconcile the numerator to the eligible denominator rather than combining separately filtered reports. A changed population can move the percentage even when underlying operations did not change.

This is first-test incidence, not reliability, maintenance quality overall, defect severity, operating readiness, or safety certification. Compare periods or targets prepared from the same rules, not an assumed universal benchmark. Product mix, sampling, schedule changes, reporting delay, exclusions, automation, and event granularity can move the value. Review absolute observations and reason-level evidence beside the percentage before deciding on corrective work.

No. This calculator applies disclosed arithmetic to values you supply; it is not an audit, quality release, maintenance authorization, supplier ruling, forecast, or process certification. Passing a limited functional test does not authorize operation or establish integrity, reliability, safeguards, or regulatory compliance. Retain source records, version the metric definition, test late-arriving events, and obtain accountable review before using the result for incentives, acceptance, or contractual action.